Mirror and Proton-cyclotron Instabilities Coexisting with Ambient Turbulence in a Proton–Alpha Plasma
Mirror and Proton-cyclotron Instabilities Coexisting with Ambient Turbulence in a Proton–Alpha Plasma
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质子-阿尔法等离子体中与环境湍流共存的镜子和质子回旋加速器不稳定性
DOI：
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发表时间：
2020
影响因子：
4.9
通讯作者：
B. Chandran
中科院分区：
文献类型：
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作者：
S. Markovskii;B. Vasquez;B. Chandran
我们研究了环境湍流对质子-α粒子等离子体中镜像不稳定性和质子-回旋不稳定性的影响。我们对胞内粒子离子和准中和电子流体进行了三维混合模拟。这些不稳定性是由垂直于平均磁场的温度大于平行温度的质子驱动的。对这些不稳定性的描述通常是基于均匀且静止的背景的假设。然而，这一假设被周围的湍流所违背。特别是，湍流涨落通过使颗粒分布函数在空间上不均匀且与时间相关来修改颗粒分布函数。我们将不稳定性的性质与均匀稳定的背景、相同的平均温度各向异性和等离子体β的情况进行了比较。我们发现，当湍流存在时，镜面模的初始增长率很接近，但饱和能级显著降低。质子-回旋加速器模的饱和能级受到的影响不大。
We investigate the effect of ambient turbulence on the mirror and proton-cyclotron instabilities in a proton–alpha particle plasma. We perform three-dimensional hybrid simulations with particle-in-cell ions and a quasi-neutralizing electron fluid. The instabilities are driven by the protons with temperature perpendicular to the mean magnetic field larger than the parallel temperature. The description of these instabilities is usually based on the assumption of a uniform and stationary background. However, this assumption is violated by the ambient turbulence. In particular, the turbulent fluctuations modify the particle distribution function by making it spatially inhomogeneous and time-dependent. We compare the properties of the instabilities to the case of a uniform and stationary background and the same average temperature anisotropy and plasma beta. We find that the initial growth rates of the mirror mode are close, but the saturation level is significantly reduced when the turbulence is present. The saturation level of the proton-cyclotron mode is not affected as strongly.
影响因子：
7.9
作者：
Chen, C. H. K.;Matteini, L.;Bale, S. D.
通讯作者：
Bale, S. D.